During the second part of the lab, students compare the activity of the same enzyme obtained from two different sources, a commercial source and a wheat germ extract. The way we do this is by tracking nitrophenol concentration increase over time. Time points are stated in the manual. Use the standard curve equation to obtain nitrophenol produced. The purpose is to obtain the enzyme concentration in the wheat germ extract.

Compare the plots obtained for each of the samples (commercial and wheat germ enzyme; scatterplots with linear trendline; slope is Vmax). Use the definition of Kp, rate constant for the formation of the product, to solve for enzyme concentration in the wheat germ extract. (Both solutions have the same enzyme, concentration is not known for the wheat germ extract, but it is known for commercial product; see the manual for the value.)

Insert a) nitrophenol amounts, b) the plot(s) depicting nitrophenol over time and c) calculation and value for [Ewg].

Kp = Vmaxc / [Ec] = Vmaxwg / [Ewg]

Commercial acid phosphatase

Tube

A410

A1

0.071

A2

0.14

A3

0.199

A4

0.33

A5

0.413

A6

0.595

Wheat germ acid phosphatase

Tube

A410

B1

0.066

B2

0.223

B3

0.264

B4

0.36

B5

0.404

B6

0.552

The concentration of the commercial product is = 0.102